SMP systems require per-cpu local clock event devices in order to enable
HRT support.  One a BF561, we can use local core timer for this purpose.
Originally, there was one global core-timer clock event device set up for
core A.

To accomplish this feat, we need to split the gptimer0/core timer logic
so that each is a standalone clock event.  There is no requirement that
we only have one clock event source anyways.  Once we have this, we just
define per-cpu clock event devices for each local core timer.
Signed-off-by: NYi Li <yi.li@analog.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

Sometimes a SMP system will randomly panic at boot.  This is due to caches
being out of sync when one core tries to signal the other.  So when one
core calls another via IPI, flush the data caches.
Signed-off-by: NYi Li <yi.li@analog.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

When testing PREEMPT_RT kernel on BF561-EZKit, the kernel blocks while
booting.  When the kernel initializes the ethernet driver, it sleeps and
never wakes up.

The issue happens when the kernel waits for a timer for Core B to timeout
(the timers are per-cpu based: static DEFINE_PER_CPU(struct tvec_base *,
tvec_bases) = &boot_tvec_bases).

However, the ksoftirqd thread for Core B (note, the ksoftirqd thread is
also per-cpu based) cannot work properly, and the timers for Core B never
times out.

When ksoftirqd() for the first time runs on core B, it is possible core A
is still initializing core B (see smp_init() -> cpu_up() -> __cpu_up()).
So the "cpu_is_offline()" check may return true and ksoftirqd moves to
"wait_to_die".

So delay the core b start up until the per-cpu timers have been set up
fully.
Signed-off-by: NYi Li <yi.li@analog.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

To set zeroes the sizeof the struct should be used rather
than sizeof the pointer, kzalloc does that.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

Bill Gatliff & David Brownell pointed out we were missing some
copyrights, and licensing terms in some of the files in
./arch/blackfin, so this fixes things, and cleans them up.

It also removes:
 - verbose GPL text(refer to the top level ./COPYING file)
 - file names (you are looking at the file)
 - bug url (it's in the ./MAINTAINERS file)
 - "or later" on GPL-2, when we did not have that right

It also allows some Blackfin-specific assembly files to be under a BSD
like license (for people to use them outside of Linux).
Signed-off-by: NRobin Getz <robin.getz@analog.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

Check that the result of kmalloc is not NULL before passing it to other
functions.

In the first two cases, the new code returns -ENOMEM, which seems
compatible with what is done for similar functions for other architectures.

In the last two cases, the new code fails silently, ie just returns,
because the function has void return type.

The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression *x;
identifier f;
constant char *C;
@@

x = \(kmalloc\|kcalloc\|kzalloc\)(...);
... when != x == NULL
    when != x != NULL
    when != (x || ...)
(
kfree(x)
|
f(...,C,...,x,...)
|
*f(...,x,...)
|
*x->f
)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

On Blackfin SMP, a per-cpu loops_per_jiffy is pointless since both cores
always run at the same CCLK.  In addition, the current implementation has
flaws since the main consumer for loops_per_jiffy (asm/delay.h) uses the
global kernel loops_per_jiffy and not the per_cpu one.  So punt all of the
per-cpu handling and go back to the global shared one.
Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

When a low priority interrupt (like ethernet) is triggered between 2 high
priority IPI messages, a deadlock in disable_irq() is hit by the second
IPI handler.  This is because the second IPI message is queued within the
first IPI handler, but the handler doesn't process all messages, and new
ones are inserted rather than appended.  So now we process all the pending
messages, and append new ones to the pending list.

URL: http://blackfin.uclinux.org/gf/tracker/5226Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

The KGDB code uses this when switching processors to make sure the icache
is in a valid state.
Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

The Per-processor Data Area isn't actually reserved by this function, and
all it ended up doing was issuing a printk(), so punt it.
Signed-off-by: NGraf Yang <graf.yang@analog.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

For systems where the core cycles are not a usable tick source (like SMP
or cycles gets updated), enable gptimer0 as an alternative.
Signed-off-by: NGraf Yang <graf.yang@analog.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

Add some notes for anomaly 05000120 to make sure we work around it.
Signed-off-by: NGraf Yang <graf.yang@analog.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

Blackfin arch: fix bug - kgdb fails to continue after setting breakpoint on bf561-ezkit kernel with smp patch

Free spinlock before call IPI handlers.
Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NBryan Wu <cooloney@kernel.org>


Header from folded patch 'blackfin_arch__fix_bug_-_kgdb_fails_to_continue_after_setting_breakpoint_on_bf561-ezkit_kernel_with_smp_patch-1':

Blackfin arch: fix bug - kgdb fails to continue after setting breakpoint on bf561-ezkit kernel with smp patch

Don't test l1 code in SMP kernel.
Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NBryan Wu <cooloney@kernel.org>

[Mike Frysinger <vapier.adi@gmail.com>:
 - handle bf531/bf532/bf534/bf536 variants in ipipe.h
 - cleanup IPIPE logic for bfin_set_irq_handler()
 - cleanup ipipe asm code a bit and add missing ENDPROC()
 - simplify IPIPE code in trap_c
 - unify some of the IPIPE code and fix style
 - simplify DO_IRQ_L1 handling with ipipe code
 - revert IRQ_SW_INT# addition from ipipe merge
 - remove duplicate get_{c,s}clk() prototypes
]
Signed-off-by: NYi Li <yi.li@analog.com>
Signed-off-by: NMike Frysinger <vapier.adi@gmail.com>
Signed-off-by: NBryan Wu <cooloney@kernel.org>

rename irq_flags to bfin_irq_flags to avoid namespace
collision with common code
Signed-off-by: NMike Frysinger <vapier.adi@gmail.com>
Signed-off-by: NBryan Wu <cooloney@kernel.org>

Blackfin dual core BF561 processor can support SMP like features.
https://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:smp-like

In this patch, we provide SMP extend to Blackfin header files
and machine common code
Signed-off-by: NGraf Yang <graf.yang@analog.com>
Signed-off-by: NBryan Wu <cooloney@kernel.org>